1. Field of the Invention
The present invention generally relates to a throttle body. More particularly, the present invention relates to a compact throttle body that is configured to reduce infiltration of foreign matter into an intake system of an internal combustion engine.
2. Description of the Related Art
Internal combustion engines generally include an air intake passage through which air is drawn into a combustion chamber. The intake passage typically extends through a throttle body. The amount of air drawn into the engine is controlled by opening and closing the intake passage with a throttle valve.
JP-A-2003-095176 illustrates a throttle body that is used to control the airflow into the associated engine. An intake manifold is positioned beside the throttle body and a fuel injector is mounted to an upper portion of the intake manifold. A main portion of the illustrated throttle body contains an intake passage. A throttle valve is positioned in the intake passage that extends through the throttle body. The throttle valve comprises a throttle plate and a throttle shaft. The throttle shaft extends generally horizontally through the throttle body. An end of the throttle shaft is connected to a throttle lever. An accelerator wire connects to the throttle lever such that axial movement of the accelerator wire causes movement of the throttle lever, which in turn causes rotational movement of the throttle shaft. A bracket is mounted to a side of the throttle body. The accelerator wire extends to the bracket. An intake pressure sensor is positioned on an upper portion of the throttle body. See, for instance, paragraphs 0034-0042 and FIGS. 7 and 8 of the Japanese publication.
The throttle shaft extends horizontally through the throttle body. Therefore, water and dust are likely to work into the throttle body through the hole that receives the throttle shaft. Also, the intake pressure sensor is positioned over the throttle body while the fuel injector is disposed over the intake manifold. In other words, the intake pressure sensor and the fuel injector are disposed generally side-by-side over the intake passage in the axial direction of the intake passage. Therefore, in order to secure sufficient space for both the intake pressure sensor and the fuel injector, the combined axial length of the throttle body and the intake manifold must be somewhat extended. The increased length of the combined throttle body and intake manifold results in the combination occupying more area within any associated engine compartment.